Astaxanthin for Management of Inflammation in Knee Osteoarthritis

Osteoarthritis (OA) is a common degenerative joint disorder that affects a significant portion of the population. Over 30 million Americans are currently affected by the disease, with prevalence expected to increase 40% by 2025 as a result of the aging population and obesity epidemic. Specifically, symptomatic knee OA is a leading cause of disability, occurring in 10% of men and 13% of women over the age of 60. Patients with symptomatic OA often experience pain, swelling, and stiffness of the knee resulting in a decrease in physical mobility which can have a drastic impact on quality of life. In addition to the significant impact on affected individuals, OA is associated with an enormous economic burden estimated at $136.8 billion annually in the US, surpassing costs of tobacco-related health effects, diabetes, and cancer. Although originally classified as non-inflammatory arthritis, recent studies suggest that a relationship exists between joint inflammation and OA. Specifically, the complex interaction between sites of local tissue damage and immune cells leads to a state of chronic joint inflammation which may play a key role in disease pathogenesis. The evidence suggesting a role of inflammation in disease progression makes anti-inflammatory agents ideal candidates for symptom management. Astaxanthin is a keto-carotenoid present in many aquatic animals, including salmon, shrimp, and lobster, that has demonstrated heightened antioxidant activity and the ability to suppress inflammation. Early evidence suggests that astaxanthin may protect against osteoarthritis in vivo, illustrating its potential as a therapeutic supplement for patients with OA. However, studies illustrating these effects in humans have yet to be conducted. This prospective, blinded, randomized, placebo-controlled pilot study will evaluate the effect of astaxanthin in reducing inflammation, controlling pain, and improving physical function in patients with advanced knee osteoarthritis awaiting total joint replacement surgery. Levels of pro- and anti-inflammatory cytokines and chemokines will be measured following the completion of a daily oral regimen of astaxanthin vs. placebo. Additionally, patient-reported outcome measurements assessing physical function and pain interference will be obtained prior to and following completion of treatment allowing for a comparison between treatment groups. Study outcomes will provide evidence to support astaxanthin supplementation as a cost-effective, added strategy for symptom management in patients with advanced osteoarthritis.